Koji has short brown hair with his bangs swifted upward and brown eyes. He usually wears a white sweater over a purple shirt and white pants. Otherwise, he's in his uniform.
Koji is a meek and friendly boy, fun loving and very supportive towards his friends. Quite obedient but at times can be devilish. He stays open to his feelings but is well aware of boundaries and what should or shouldn't be done in situations. As seen he usually stops Haneru from getting into fights and has to put up with Hiroto's stubbornness.
He has average acedemic abilities, not great but better than Haneru.
He's Haneru's best friend and chilhood friend. He's a little sad that Haneru is drifting away from him since now he's all about dancing but still wants so support him as a friend. He and Haneru are often seen to hangs out together.
He's Hiroto's childhood friend, they're still in touch but not as much as they used to since Hiroto is being bitter towards Haneru's dancing and he's not good at basketball to play with Hiroto. However, he still gives advice and see Hiroto as a friend. Later, after resolving the conflict between Hiroto and Haneru, they hang out toghether like they used to again.
Ayumu is Kanon's friend, he met her a couple of times. When Ayumu's trying to make Haneru and Kanon a couple, he had to help her set them up but it didn't worked out in the end. Ayumu developed romantic feelings towards him in the end but he's still seems to be oblivious about this.
He and Haneru drank 150 bottles of Rocket Cider and to get points and won 2 Jey El's concert tickets.